Lots of technical improvements

scripts/check-i18n.mjs

@@ -0,0 +1,65 @@
+#!/usr/bin/env node
+// Verifies that all i18n translation files share the exact same set of keys.
+// Exits with a non-zero status (and prints the differences) if any key is
+// present in one language but missing in another, so CI can catch drift.
+
+import { readFileSync, readdirSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const scriptDir = dirname(fileURLToPath(import.meta.url));
+const i18nDir = join(scriptDir, '..', 'src', 'assets', 'i18n');
+
+function collectLeafKeys(value, prefix, keys) {
+  for (const key of Object.keys(value)) {
+    const fullKey = prefix ? `${prefix}.${key}` : key;
+    const child = value[key];
+    const isNestedObject = child !== null && typeof child === 'object' && !Array.isArray(child);
+    if (isNestedObject) {
+      collectLeafKeys(child, fullKey, keys);
+    } else {
+      keys.add(fullKey);
+    }
+  }
+  return keys;
+}
+
+function loadKeys(fileName) {
+  const content = readFileSync(join(i18nDir, fileName), 'utf8');
+  const parsed = JSON.parse(content);
+  return collectLeafKeys(parsed, '', new Set());
+}
+
+const files = readdirSync(i18nDir).filter((name) => name.endsWith('.json'));
+if (files.length < 2) {
+  console.log('i18n check: nothing to compare (fewer than two language files).');
+  process.exit(0);
+}
+
+const keysByFile = new Map(files.map((file) => [file, loadKeys(file)]));
+
+const allKeys = new Set();
+for (const keys of keysByFile.values()) {
+  for (const key of keys) {
+    allKeys.add(key);
+  }
+}
+
+let hasError = false;
+for (const [file, keys] of keysByFile) {
+  const missing = [...allKeys].filter((key) => !keys.has(key)).sort();
+  if (missing.length > 0) {
+    hasError = true;
+    console.error(`\n[${file}] missing ${missing.length} key(s):`);
+    for (const key of missing) {
+      console.error(`  - ${key}`);
+    }
+  }
+}
+
+if (hasError) {
+  console.error('\ni18n check failed: translation files are out of sync.');
+  process.exit(1);
+}
+
+console.log(`i18n check passed: ${files.join(', ')} share ${allKeys.size} keys.`);